Variable speed transmission mechanism



March 3, 1936. D. E. Ll-:WELLEN ET Al..

VARIABLE SPEED TRANSMISSION MECHANISM Filed Oct, 4, 1932 3 Sheets-Sheet l Orto/mm3 March 3, 1936,

D. E. LEWELLEN ET A1. 2,032,585

VARIABLE SPEED TRANSMISSION MECHANISM Filed OG.. 4, 1932 3 Sheers-Sheet 2 fmma/MZ ell/el fie/1 lPatented Mar. 3, 1936 UNITED STATES -VARIABLE SPEED TRANSIVIISSION CHANISM MIE Darcy E. Lewellen and Emmons F. Lewellen,

' Columbus, Ind.

Application October 4, 1932, Serial No. 636,204 1o Claims. (oma-230.17)

This invention relates to improvements in variable speed transmission mechanism and it is an object to simplify and improve generally mechanism of this character.

5 Referring to the accompanying drawings,

which are made a part hereof and on which similar reference characters ndicate similar parts,

Figure 1 is a plan view of kthe device,

Figure 2, a side elevation,

Figure 3, a section on line 3-3 of Figure 2, Figurei, a side elevation showing the several Apositions of the controlling element for the variable speed transmission pulleys,

Figure 5, a side elevation of a modified form of the device,

. Figure 6, a View partly in side elevation and partially a section substantially on line 6-6 of Figure 7 in which the roller is positively positioned, and

Figure 7, a section on line 1--1 of Figure 6.

In the drawings numeral 9 indicates a frame having shafts I0 and II journaled therein in suitable bearings I2 and I3 secured to the frame.

The shafts extend beyond the sides of the frame and carry sprockets, pulleys or gears, not shown, by means of which the shafts are driven and by means of which they drive other devices. 4Power is applied to the sprockets, pulley or gears on one of the shafts and power is taken off from the other shaft in amanner well known. Conical faced disks I4 and I5 are mounted on shafts I0 and II respectively. The disks are splined to theA shafts on which they are mounted so as to rotate with the shafts but are free to move laterally along the shaft.

Collars I6 are secured to the shafts by set screws I1 and between these collars and the outside faces of the disks I4 and I5 are positioned compression springs I8, these springs surround- `ing cylindrical extensions or hubs I9 on the disks I4 and I5. The tension of the springs I8 may be controlled by adjusting the collars I6 laterally on the shafts and securing them in adjusted position.

A V-shaped belt 20 is mounted vabout the cone I faces of the disks by means of which belt one shaft is driven from the other. The belt may be of any suitable construction having edges lying at an angle to correspond to the angle of the conical faces on-the disksr I4 and I5. The disks are held in frictional driving contact, with the belt by means of the springs I8.

The frame 9 has upwardly extended lugs 2| having a shaft 2.2 mounted therein. A yoke 23 is pivotally attached to the shaft 22 so as to swing about the shaft. The lower end of the yoke 23 carries a nut 24, the nut having bosses 25 which extend through slots 26 in the yoke. A screw 2'I is threaded through the nut 24 and is'operated by means of a handwheel 28. Collars 29 on the shaft. 21 hold the shaft 21 against endwise movement; The yoke 23, Figures 2 and 3, has slots 30 in which bearings 3l are slidably mounted and a shaft 32 is mounted in the bearings 3|. Springs 33 support the bearings and aroller 34 is mounted upon the shaft 32. In Figure 2 this roller is held in contact upon the belt 20 by means of thesprings 33.

From the description that rotation of the handwheel 28 will swing yoke 23 on its pivot and move the roller 34 toward one of the disks and away from the other. As the Aroller 34 moves toward one set of disks, these disks are necessarily forced apart. This decreases the effective diameter of the cone faces in this pair of disks. As the roller 34 swings away from the opposite set of disks, these disks are free to'come together under the urge of the springs I8, so that the effective diameter of the cone surfaces of these disks will be increased. By swinging the lower end of the yoke 23 to the right as viewed in Figure 4 to bring the roller 34 to the full line position as shown in Figure 4, the effective di ameter of the cone surfaces on disks I5 will be decreased, since these disks will be forced apart,

given it will be apparent so that the belt 20 will assume the positions shown in full lines in Figure 4. If shaft II is the driving shaft and shaft III the driven shaft, it will be apparent that, when in this position, the shaft I0 will be driven at a much slower speed than the driving shaft II. -The shaft II is driven from some source of power and the shaft I0 drives the mechanism which operates the work.

When the handwheel 28 is operated clockwise, the disks I4 will be moved apart and the disks I5 toward each other and the belt 20 will then assume the position shown in the dotted lines, when shaft I8 will be driven at a much faster speed than shaft II. When the handwheel 28 is rotated in the opposite direction, the belt will then assume the position in full lines again (Figure'4).

It will be apparent that the position of the disks I4 and I5 will depend upon the position of I the belt 20 and that this belt is positioned by the roller 34. In Figures`2, 4, and 6 the roller 34 is always in `contactwith the belt 20 on the direct line between the center of the shaft 32 and the shaft I0 and between-.the center of the shaft 32 andthe shaft II, thus positively positioning the belt in each pair of disks The enecuve d1- ameter of the belt 20 on disks I4 and I5 is controlled by the roller 34. J The roller 34 has a band 42of non-metallic frictional material and slightly widerthan the roller. The outside edges of the band 42 are beveled as shown at 33 and'at thev same angle or bevel of the conical faces of the disks I4 and I5.` The band 42 prevents wear on the roller and also assists in transmitting power from one pair of disks to the other.

The shaft 22 has collars 39 secured thereon by set screws 40 which hold the shaft 22 against endwise movement and consequently hold the roller 34 from endwise movement In Figure 1, the yoke 23 is fixed to the shaft 22 by means of a screw 4I. In this case the roller 34, therefore, is held in fixed sidewise position with reference to the shafts I0 and Il. v. v

In case there should be any slight difference in the tensin of the springs I3 or in case any of. the disks I4 and I5 should not move'free on the shaft, then the swinging of yoke 23 about the center of the pivot shaft 22 will positively position the` disks toward which the roller is moving and allow the disks from which the Yroller is moving to move an equal amount. Iny other words, the roller keeps the disks centered in the transmission and maintains the belt 20 in correct alignment on the disks.

The width of the beveled faces of roller 34 is slightly less than the exact' distance between the disks at this point, so thatnormally the roller will not be in engagement with the disks but in case the spring tension of the springs I3 is not exactly the same or in case one of the disks should not move freely on the shaft, then the roller 34 will always alignthe belt and the disks. 'Ihe diameter of the rollerv 34, Figures -2 and 4, is'such that'it is in engagement with the belt at its effective diameter in both pairs of disks. In Figure 2- this result is secured by providing a resilient mounting for the shaft 32, because of the variation in the position of'the belt due tothe angularity of the belt, does not permit the shaft 32' to s move on a true radius from the shaft 22.

To illustrater Assuming that both pairs of disks are 20 inches in diameter and that the length of belt is such that the effective diameter at which the belt is located in both pairs of disks is 15 inches, ncw if the disks of one pair of disks are moved toward each other a sufilcient distance to move, the belt radially outwardly 2 inches, changing the position to a 17 inch effective diameter, thenthe disks on the opposite shaft would have to move awayfrom each other `a greater distance in order to reduce the eective belt diameter to less than I3 inches. Due tothe L angle at which the belt runs, it is necessary that opposite the roller 36, appreciably stronger than the springs on the disks with which the roller engages, this providesthatthe'spring will cause the belt to follow the r5 11er`33 in the disks'but [alsof insures separation of the disks. engageble.`

bythe roller 35. I

In Figure 5 the belt 35 is controlled by the roller 36. This roller operatesl directly against the belt and controls the spacing of disks 31 fromeach other. TheI disks 31 of course, `are urged toward each other by springs, not shown, and are limited in'their movement toward each other by the belt and the roller 33. 'Ihis construction would provide an yoperable transmission.

Figure 6 shows a slightly differentconstruction from Figures 2 and 3. In Figure 6 the shaft 53 carrying roller 43 is mounted in bearings which are xed in relation to the yoke 44. 'I'he shaft 45 is mounted in extensions 43 on the frame, the

same as shown in Figure I. ,In Figure 6, however, the top extension of yoke 44 has a slot 41, the shaft 45 passing through the slot. In addiv tion to shaft 45 the extension 43 also carries shafts 50. These shafts carry rollers 43 and 43. On

rests against roller 43 isv of 'such shape that it raises the yoke 44 in the slot 41, bringing the center of the shaft 53 nearer the center of the shaft 45. 'I'his causes roller 43 to move toward i -shaft 30 a distance greater than the'distance it has moved from shaft 3|. The yoke .44 is adjusted by means of a shaft 53 which is threaded through a block 55, the ends of which engage slots 53 in the yoke y44. Collars- 51 holdl the shaft 53 against endwise movement. The shaftis operated by hand wheel 53. Collars "fand '33 are mounted on shaft 45 and held infposition against the slotted sides of the yoke 44 by suitable screws Vt4', these collars prevent sidewise movement of the yoke.

materially simpliiles they construction and reduces the cost of variable speed transmissions.

It will be obvious to those-y skilled in the art that various changes may be made in my device without departing from the spirito! the invention and therefore we do not limit ourselves to what is shown in the drawings and described in the specification, but only as indicated by the appended claims.

Having thus fully described our said invention, what we claim as new and desire/t0 secure by LettersPatent, is: 'f

-1. A variable speed transmission device comprisinga pair of shafts each carrying a pair of discs with conical interior faces, both discs of each pair of discs being keyed to but axially slidable on the shaft, va beit carried by the said discs, resilient means for holding the disc faces against the blt, and resilient means for positioning the belt, substantially as set forth.'

2. A variable speed transmission comprising a pairr of shafts having cone-faced pulleys,`each pulley comprising a. pair of movable separable discs, a belt connecting said pulleys,y resilient means for holding the discs of each pulley in engagement with the belt, a Pivotally mounted roller engageable with said belt for tensioning the same, and means movably supporting said roller for adjustment toward either of the pulleys while maintaining the portion of the periphery of said roller that is in contact with the belt adjacent the 75 plane of the `pulley shafts during such adjustment.

3. A variable speed transmission comprising a pair of shafts having driving and driven pulleys mounted thereon, each pulley comprising' a pair of discs having inwardly extending cone faces, a belt mounted about said pulleys, resilient means operating to move each of the discs toward each other and into frictional contact with the sides of the belt, and a roller pivotally mounted intermediate the pulleys and movable toward and from one. of the pulleys, said roller being in engage- Vment with the belt to separate the discs when moved toward the pulley and thereby decrease the eiective diameter with which the belt engages and to permit eachof the discs to move toward 'the other to' increase the eiectivediameter when the roller is moved away from the vroller being movable toward either of the pulleys to vary the effective diameter of this pulley and thereby increase the speed of the shaft upon which this pulley is mounted in'reiation 'to the speed of the adjacent shaft, substantially as set y forth.

,5. A variable speed transmission comprising a pair of shafts, each carrying a pairvof discs with conical interior faces, said discs beinglkeyed but laterally slidable on the shafts, a belt carried by the said discs, resilient means for holding the discs in engagement with the belt, a single movable roller engaging the beit and means adjustably lsupporting said roller for movement from a position in which the portion of the periphery thereof in engagement with the belt lies between one of said pair of discs to a corresponding position with respect to the other pair of discs.

6. A variable speed transmission comprising a pair of pulleys journaied on fixed parallel axes, each pulley including apair of axially movable cone-faced ses and resilient means for urging the discs together, a V-belt connecting said' pulleys, a pivoted roller engaging said belt with A each pulle of the transmission.

the belt-contacting -portion of its periphery lying substantially in the axial plane of said pulleys and means for moving said roller toward one pulley and awa'y from the other to move the belt radially lon each pulley and thereby change the speed-ratio of the transmission..

7. A variable speed transmission comprising a pair of pulleys journaled on fixed parallel axes,

each pulley including a pair of axially movable cone-faced discs and resilient means for urging the discs together, a V-belt connecting said pulleys, a pivoted yoke straddling saidbelt between said pulleys, a roller yieldingly supported in said yoke and engaging said belt, and means for moving said yoke to shift the relation of said roller and said belt to said pulleys.

8. A variable speed transmission comprising a pair of pu leys journaled on fixed parallel axes, including a pair of axially movable cone-faced'discs and resilient means for urging the discs together, a V-belt connecting said pulleys, a lever pivotally supported for movement in a plane parallel to the plane of said belt, means for shifting said lever longitudinally as the same is turned about its pivot, and a roller pivoted to said lever and adapted to engage said belt to move the same radially on the pulleys and thereby change the speed-ratio of thetransmission.

9. A variable speed transmission comprising a pair of shafts having variable diameter pulleys thereon, a V-belt connecting said pulleys, a pivoted yoke straddling said belt between said pulleys, I

belt-engaging means including a spring-supported roller on said yoke, and means for moving said yoke to shift the relation of said belt to each of said pulleys and thereby change the speed-ratio of the transmission. y

10. A variable speed transmission comprising a pair of shafts, a pair of cone-faced discs keyed to each shaft and forming variable-diameter pulleys,each disk of each pair being ax/ially movable upon its shaft, resilient means for urging the discs of each pair together, a V-belt connecting said pulleys, a pivoted roller movable in the lplane of said belt and restrained against transverse movement, said roller engaging said belt and'engageable with said discs to aline the same lwith the belt, and means for moving said r oller ,to shift the relation of said belt to each of said pulleys and thereby change the speed-ratio 

